Safety joint



Fehzz, 1949. C. R EDWARDS 2,462,477 A SAFETY JOINT Y Original Filed May 13, 1940 I 3 Sheets-Sinaai. 1

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agli x l CHnRLs R. EDWARDS,

Feb. 22, 1949.

Original Filed May 15, 1940 c. R. EDWARDS SAFETY JOINT 5 Sheets-Sheet 2 CHneLss E. Eon/Heos,

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Feb. 22, 1949.- c. R. EDWARDS 2,462,477

SAFETY JOINT Original Filed May 15,` 1940 3 Sheds-Sheet 3 l l e f1 7U/ 2 @l g 65/ f 7m? y 71h/ j 6?/ 49 N 75 I j 74', br

76/ 76' 774 f i JF 9, 52V i tral portion of said bore is slightly reduced so as to provide a shoulder 31 therein. Attached to the lower end of the housing 33 is apin 38 which has its upper end externally screw-threaded so as to correspond te and coact with the screw threads 35. Its lower end-39fis externally,screw-threaded so as to receive a tool joint (not shown). The pin 38 is provided with an axial bore 43, and the upper end of said bor-e is screw-threaded at 4I so as to receive and firmly secure the clutch nipple 42. The outer surface of said clutch nipple is provided with two rows of wedge cams 43and 43, and in the space between therows of wedge cams 43 and 43' is a ball raceway 44 (Figs. 4 and 5); and in the space above the row .of wedge cams 43 isa ball raceway 44. Surrounding the clutch nipple 42, and Vextending upwardly, is a slidable sleeve 45 which snugly engages the inner surface of the member 33, Vand is movable within the bore 36. The lower ,end of said sleeve 45 is provided vwith a plurality of openings 46, and con'- ned within said openings are locking balls 41. The hollow sleeve 45 is bent circumferentially inwardly at 48; so as to receive a packing ring 43.' The sleeve 45 movably engages the upper surface of the enlarged part of the bore 33, and is provided with a shoulder 50 which corresponds to and coacts withthe shoulder 31 of the member 33. The upper end i of the'sleeve 45 is internal- 1y` screw-threaded to receive the spring retainer 59 and this also retains the packing 38. Spring retainerv 59 additionally functions as a piston to move sleeve 45. A recess 52 is provided above thethreads 35 to receive a packing ring 53 which is insertable therein. A stop ring 54 overlies the topgof the clutch nipple 42, and has an upstanding top collar 55 which abuts the shoulder portionV 48 when the sleeve 45 is moved downwardly against the collar 55, which Yacts as a stop.

The lower beveled edge of the ring 54 acts as a ball retainer for the balls 41whenever the lock is -removed from the housing 33 and when the safety. threads 35 are released. Resting on the ringv 54- and slidable within the inside reduced diameter part 48, is a sleeve spring seat 56 which has Yits upper end 51 flanged outwardly to receive the coil vspring 58. The coil spring 58 is confined above Vby a retainer 59 which is attached to the `upper screw-threaded portion 5I of the Ysleeve 45,'normally resiliently holding the sleeve 45 elevated.. The retainer 59 is provided with a packing ringv 68. A bleed hole 6| is provided in the body 33 kadjacent to the shoulder 31 so as to equalize the fluid pressure.

One or more, preferably several, of these safe-A tyjoint's may be inserted, as indicated above, at short intervals in that part of a string of pipe or of tubes that laterfin use may becomerlodged or stuck inY a bore. A suitable number of these joints are assembled with variously tensioned springs in each of the joints, and the joints may be madeup into a string of pipe in such a mannerythat the joint at the bottom will have the weakestspring 58, and the next joint above in thefstring will be the next weakest and will increase the tension so that theV top joint will have the strongest spring 58. Y A

When Ythe rst joint is made up in a string and before the viluid pressure has become so great as to compress the spring 58 by forcing the sleever then the spring 58 will urge the 45 I downwardly, sleeve Y45 upwardly until the top of the spring seat V59 will *bear upwardly against the lower end of the pin i342 Inthis elevated position of the sleeve 4,5,.itheclc'cking .balls 41 will-also'be elevated, and

will be engaged in the upper row of clutch cams 43 so as to prevent reverse rotation which would cause parting of the'safety threads 35. When the pump is running so as to remove the cuttings from the bit, as in drilling, then the pressures withinthe vjoint will beesofgreat, as: to :compress the Asprings 58.?inf1all thesafetytjoirits, an'd then the sleeve 45 will be forced down until the shoulder 58 of said sleeve is resting on the shoulder 31 (Fig. 1) of the housing 33; said locking balls 41 will also be lowered and will be in engagement with the lower row of 'clutch cams 43', and in this position, thevjointwill be locked so as to prevent reverse rotation to unscrew the safety threads 35 while drilling.

Thelocking ofthe joint between the sleeve 33 andpin 38 takes.` place as follows: It has been pointed out above that the sleeve 45 snugly engages theinner surface of the member 33, and also two packing rings 4S yand 60 are disposed between the member 33 and sleevefllill Thus-there is a frictional engagement lbetweenthe sleeve 11151 and the member 33 and upon reverse'rdtationof the member 33'withthe lockingballs1-"41'inefigagement with eitherof the-rowsi'offclutchams'f 43 or 43', the sleeve' 451is'also-reverse1y rotated@ to carry the balls 41 up theifin'cline"ofthecalis"V 43 or 43 until the balls. contactthe insidefof the? member 33. Upon slightlyfurther"reverse'rotal'v tion, theiballs 41 are-rotated Yand thsfreed jirl-'s' to tight locking position ;-there being no need for`- the sleeve 45 to press the balls 41- with'fanygreat force up the inclines of thecams'to'tiglitlyflck the member 33y and nipple 42 together, a'n'fgi-ithil'sf` also lock the v'member 33 and ,pin`38i-togetlierAv since, as described above,'nipplei42` is'111'y-secured to--pin 38. Y

When it isldesiredfto-unlock ary'"particular?` safetyjoint, preparatoryfto unscrewingethefsafei ty threads 35,V andzto release this 'particularfsafelf tyjoint, an intermediate luid-pressure'isfbuiltlpl with the pumps until the inside pressure-acting? on the upper part-of the s1eeve'45-, ile.; thelpls'`v ton 59, is sufficiently greater"thar'the-outside pressure acting uponthe shoulder 505o'f'the sleeves 45, that this diierential in pressure at thvi'sffpaivi ticular joint is suiiciently great to partially `'move the sleeve 45 downwardly until the'slee've45ialnd' the locking balls are-inthe positionoffthe"`parts' as indcatedin Figs; 2 ande, whichivillmove the locking balls into the ball raceway- 44; j The ystrengthV of each spring being' known, v thegapproximate intermediate differential of pressure actingfupon the-upper part of thek sleev;"i.el,"th" piston 59,- and the shoulder 50,' oraflrelativelyf narrowl such differential pressureV range for f each l joint'is also known, and hence the range offsucl'i'" diierential pressure for any 'joint may be work'd through in small increments, reverse 'rotation'A being attempted after eachincremental'increase' insuch diierential pressure'.LY In'general, such diierential pressure range *for thelowermost" joint is worked througnfirstandif reverse'"ro-L tation is not obtained, the Vpressure"is"increased to the next highest such diierentialpressre range correspcvnnding"to the 'next highest joint, and this *differential pressure"1a`nge' "'w'il-ied through as before.' .ThisprQcess is -continued.i1l"' til a joint is reached at which reverserotal'tl'iifiils4 obtained; with disparte-inV theracewy shown in Figs. 2 and 4 at a joint atiwhich r en" is obtainable, the safety'jointcanbe.slightlyroftated in a reverse and counterclockwise 'difeto'f and will be partially unlocked to Y'such.an'fezitla'iitl thatnow theiupperipa'rt tortue' joint can b turned'K in a reverse direction until the locking balls 41, along with the sleeve 45 and the upper part of the joint, have been relatively elevated up far enough so that the locking balls will be forced up into the upper row of clutch cams and will prevent, for the time, any further reverse rotation. The pump is stopped or the uid pressure within the joint is released, which will then permit the spring 58 to expand upwardly to lift the sleeve 45 and move the locking balls 41 to the raceway 44 above the upper row of clutch cams 43 due to the fact that the member 33 and sleeve 45 have been elevated upwardly relative to the nipple 42, at which time the upper part of the joint may be further rotated in a counterclockwise direction until the threads 35 are completely unscrewed, and at such time the joint will have been released so that it can then be withdrawn from the well. However, if for any reason it was found desirable to reconnect the joint, it could be done without coming out of the well to reset any of the parts thereof. Also, it will be seen that all three oi the packings and all parts of the control except the nipple 42 were removed from the lower portion of the joint. It is pointed out that only the lower portion 38 of the joint and the nipple i2 are left in the well. It will be observed that because it is necessary not only to have an intermediate iiuid pressure to operate the locking means, but that it is necessary to .'"i

operate a number of variations, it might be said that the lock is a foolproof one and substantially all possibilities of the joint becoming unlocked and released during normal operations in a bore hole are eliminated. Also, it will be seen that l' such a safety joint is Very strong, and that it is no longer necessary, to lose any substantial parts of the lock or packings at any time.

In Figs. 6 to 10, inclusive, there is shown another form of a safety joint which is somewhat similar to the type shown in Figs. 1 and 2. In said Figs. 6 to 10, a pump pressure is applied to the movable, hollow, piston head or block 6I which has its lower end retaining the balls 62. The lower end 63 of the joint has its outer surface cut inwardly to form an annular shoulder 64. An annular metal ring 65, having a ratchet clutch, may be placed upon said shoulder and welded at 66 so that said member 63 is capable oi receiving varying lengths of the upper structure. The object of this construction is to reduce the cost of manufacture and to permit easy and exact matching oi the two opposing coacting halves of this clutch without requiring extratime andvspecial shop equipment to form the clutch faces. The structure shown in Figs. 6 and 7 operates very similar to that shown in Figs, 1 and 2, and in place of the packing ring 49 being below the spring, it is above the spring in Figs. 6 and 7; thus showing another form for operating a safety joint in the same manner. Fig. 7 illustrates the manner in which the spring 54 functions as a ball retainer for the ball 62 when the safety threads 35 are released. The ring 54 functions in a similar manner as described previously.

In Fig. 11 there is shown an example of still another form of the safety joint, having a tubular body 61 with its upper end 68 internally screw-threaded and its lower end 69 provided with an internal-safety joint thread. The thread 69 may be right-handed or left-handed. An adaptor 10 is provided, and is attached to the upper end lili of the member 67. The adapter lli has a depending, elongated sleeve 1I which snugly engages the inner surface of the member 61,

lower end of the sleeve 1I. The member 13.591,5,l i i Y, im axial bore thelfethrough, and said bore is en-f larged at the lower portion oi the member 'I3 thereby forming a shoulder 15. The lower portion of the member 13 holds the balls 15, which are identical to the balls described in the previous gures, and they operate with rows of cams "il and 11' which are integral with the upstanding portion of the pin 18. Confined between the upper end of the member 13 and the adapter 1.0, is a coil spring 19. At the upper end of the pin i8 is a ball retaining ring 30, and conned between the bearing ring and shoulder 15 of the member 13, is a coil spring 8l. When the joint is assembled, the heavy spring 19 will act down-` wardly, thereby moving the balls 16 so that said balls will become engaged within the lower row ci the cams 11', and thereby locking the members t? and 13 together. Fluid pressure passes through the joint, but ordinary drilling pump pressure on the fluid will act upon the member 73, and the joint is still locked together, but now in the upper -row of cams 11. However, when it becomes desirable to disengage the joint, the pump pressure is lowered so as to only partially compress the spring 19, and act on the lower shoulder 15 of the member 13 to move said member upwardly against the tension of the spring 19. The spring 8l will also help to move the member 13 upwardly. This movement will move the balls 16 upwardly into the raceway 16', and the joint $9 may at that time be broken until the balls 'i6 contact the next cam 11; pump pressure is increased so as to again move the member 13 upwardly. It is pointed out that the movement of the member 13 upwardly is limited by the sleeve ll of the adapter 1. When the balls 15 snap through the upper row of cams, they are then iree to be moved so that the joint 69 may be completely disconnected. It is pointed out that below the cams is a packing ring 82 which is engaged by the lower end of the member 13 so as to pack oit against escaping pressures. Also, it is an object to seal and pack oi the threads 68 as well as the threads 69.

it is believed that the advantages of eachrof the foregoing constructions are obvious, but these may be partially summarized as follows:

All three embodiments comprise locking means which may be operated from without the well; that is, by increasing or decreasing the pump pressure, a safety joint may be locked or unlocked. Furthermore, all parts of the safety joint are removed when it is unlocked, except for the extreme lower pin and nipple; thus saving considerabie expense and avoiding waste. In addition, it is to be emphasized that the safety joint in'each embodiment comprises hollow members so that there is no interference whatever with the passage oi the tools, core barrels and the like.

through the pipe string.

This application is a division oi my co-pending application, Serial No. 334,947, led May 13,

1940,V for Methods of and means for recoveringV elements from well bores now Patent No. 2,394,759 issued Feb. 12, 1946.

Other modes of applying the principle of my invention may be employed instead of the one explained, change being made as regards the mechanism herein disclosed, provided the means staten byanii of the followingclaims. orA the.

equivalen't-offsuchl stated means be employed.'

I-'tlierefore,l particularly point out and distinctlyfolanr as 4my invention:

n azstri'ngof' pipefor awell' bore, av safety jointi'comprising a'housing, aslidabl`e sleeve in sadhousing having locking and unlocking posi-l tions, aeclutch nipple mounted withinsaid sleeve, reliable elements carried by openings in said sleeve! and a row. of circumferentially arranged' camwedg'e 'faces carried; by said nippleA adapted tei'c'o'operate withsaid elementsto lock said housing". andi nipple together,y a raceway on said nipple arda-cent said roviI of carnowedge faces, anda.

spring. in the housing. yieldingly urging thensleevev toward; one of said positions;

' 2;l The; structure set forth in claim? 12 wherein said: sleeve. has an: internal shoulder' and said` sleeve.'- ha's: an annularA spring: seat -on its upper endipsaid spring engaging said shoulder'fandsea't.

rElieV structure set vforth in claimA 1 wherein' saidi sleeve includes'.V an'.V annular spring retainer',

andaring.' member slidable within said sleeve abovelsaidrollable elementsl and normally seatefdfon-:the'- upper end of said nipple, said spring engaging said retainer 4and ring member, said ringimemberengaging said' rollable elements upon-separation--of Isaid nipple and sleeve vto retainA the-same in saidl openings.

ingi-'Inounted-between said shoulder and the up perl-endL o' said sleeve,v an annular spring seat orrtlieiinterion of l said sleeve,- and a. second spring mounted between said annular spring lseat and th'efup'per .end-of: said-nipple, said second' spring beingfof! smaller magnitudeV thansaid rst named spring.

G fInia string of pipe for-.a `well lbore,rasafety jint;.comp1ising .a housing,-as1id'able sleeve in' said housing, said sleeve havinganannular spring. l'

retaineiesecured: to'its f upper end, aelutch nipple mountedwithinfsaid :sleeve andY having .anl an.-

nular spring' seatonf-ts, upper end, a. spring;

mounted between said retainer .andI seat, rollable elementsi'carriedby openingsthrough said sleeve and-spaced circumferential rows of cainwedge faces carriedby said nipple adapted to cooperate with. said-Yrollable elements to lock said housing andinip'ple. together, and a raceway on said nipple between ysaid rows of canrwedge faces.

Y'1."'1na string oflppe for a wellbore, ai. series Yofsa'fety, joints, said joints each comprising a housing; a Vslidalole sleevein said housing having.l

' The structure set forth in claim 1 includ- I lockiiigf'arid? unlocking positions av clu't'eliv nipple mounted within said sleeve; rollable elements cz'irried lyf openings through said? sleeve and al row: of circumferentially arrangedf cam wedge` faces Vcarril-3dby said nipple adapted'to cooperate with;saidelementsftoflocklsaidhousing andnipplef together; earaceway-f' on rsaid' nipple adiacent said row.' of; 'cani wedge: faces,` and aspring in thev Housing, yieldingly urgingf the sleeve` toward one ofsaid' positions, saidf` springs int-said' joints being progressively stremgerupwardly-A of said seriesV of! jointsa-to;retain` the: rollablei elements in locking position ati correspondingly increasing iiiiid pressnres;V

8; anstring". of." pipe-I for al. well'. bore, a. series oifnts;v .said` joints.-` each' comprising a sleenhafving amarmular spring retainer secured tei itst ripper'end'y` ai clutch-1 nipple mounted` withinsanlzsleeue andz'haivnig an annular' spring. seat upperend', ,a Lspriifi'g mounted between. said retainer .ands seat,. .rollable elements carried by openings.: thronglii said :sleeve .andi spaced cir-- cunrfenentialA roi/vs. r of.' .cam wedge facescarried. bysai nipplefadapted to cooperate with saidV roilableaelements fto: lock saidhousng and nipple together; iandga.rraceway .en said Vnipple' between saidzf'erows .of cam` wedge Ifaces, said springs in saidvloi'ntsv .beingprogressivalyf stronger upwardly saidwseries of' vjoints @tof retain the. rollable.

elements i in` locking; :position att .correspondingly inei:easing.:fluidpressures.Y

V9;.;Eor use'in` a=.-safety joint inf awellpipe including-housingzandtf .pinuelements andzrollable elementsfshiftable to. locking and-unlocking. posi.-

' tions with the first :elementsyvaatukrular nipple having; .spaced ci-rcumferen'tial series vof camwedge faces extendnsfitherearound and a race.- way.; forsreeeivinggsaid rolla'ble elements between saidawedge faces,fand means lfor rigidlyv connecting thenipple withsaid pinfelement.

A10.-. Eorffus,e inrav safety` joint in a well .pipe inciudingfhousingeandfpin' elements Iand rollable elementsshiftableftolocking and-,unlocking positions with ithe. rst elements; a. .tubular ,nipple integral: with saidepinelement :havingY Aspaced circumferentialfseriesotzcamwedge faces' extending. therearoundfand araceway :for receiving.; said rollable elements Iloetweenfsaid wedge faces.

CHARLES. R. EDWARDS.

REEERENCES- CITED- Y The following references :aref vof record in theA meer; thisipatfent:

Um'rniafsfrsrne LPATEnfre.

Number l Name Date 1583725639; '-Wiekersliarn Dee-'22, --1931 159619,4311 `-Skinner Aug-7, 1934:1v 2,202,261 Osmun -Maye28f1940 2%2I8496l Phillips; Oct.15,` 1940 

